My front offside wheel has been making some strange noises lately. I jacked the car up to investigate this morning and discovered that the 24mm hub nut was actually loose!!

I tightened it as much as I could by hand and then moved it back slightly so that the recess in the nut was in line with the recess in the axle shaft and then used a punch to lock it into place...

My haynes manual says to tighten the nut to 38lbf ft (52Nm) and then loosen by 90 degrees, then lock the nut by staking the locking collar to the axleshaft; I dont have a torque wrench and wouldnt know how to achieve the settings qouted by my haynes manual?

Is it safe the way Ive done it and does the recess on the nut have to line up with the one on the axleshaft or can it be punched into place anywhere around the nut?...

They are one of the key items that *need* a torque wrench.

The nut used is called a "stake nut" and comes with a collar with no indentation. You use a fresh nut each time, torque up to the spec given in the book and punch in a bit of the collar to the groove in the shaft. They are cheap compared with the machining a castle nut requires in the factory but not as good for this reason.

FWIW, I've known people re use stake nuts but I really wouldn't. You fatigue the collar where you keep bending it, causing it to be weak and have every chance of removing the locking feature. Given yours has already come loose, I'd want a fresh nut on there pronto. I'd also be looking very carefully at the wheel bearing given whats happened to it. They are cheap for a kit (both bearings, oil seal and fresh stake nut come in a kit for about £20 from memory) and try to borrow a torque wrench if you don't want to buy one. You can't do the job without, there just isn't a way.

Thanks Chris, this is a great help. Im guessing then that the wheel bearing's knackered due to me having driven around with the stake nut loose?

If I borrow a torque wrench will it have the settings marked out on it suggested by my haynes manual? Im guessing I will have to then loosen the nut by 90 degrees before punching/locking in to place as also suggested by my haynes manual?...

Is it possible to buy stake nuts on their own and if yes, where from?

http://www.volvo300mania.com/technical/ ... ension.pdf

P32, section J.

Yes, it is the fact it's run loose that makes me think the bearing could have seen wear outside of what it expects. They arn't horrible to do once you have done one, if that makes sense. There is a knack to getting the outer shells out of the hub. I did one of the Corset (pretty much the same) in half an hour yesterday, my first one on the 300 took a day and a trip to a friendly garage to get the shells out for me. They showed me the knack, I put a fiver in the biscuit tin, life has been easy since.

52Nm (yup, that will be on a 1/2" drive torque wrench, they normally have a screw turn adjusty thing then a lock bolt) then slacken 90deg, then stake the nut.

Hub nuts used to be available separate from Volvo, but now NLA. According to Mac, they are 15/16"AF Threaded 5/8" 18tpi. Deep stake nut - http://www.volvo300mania.com/forum-uk/v ... 18#p160418

I'd suggest you buy the kit that (again, Mac) is listed here http://www.volvo300mania.com/forum-uk/v ... 0&#p166620 . That is a very good kit for £15, I paid £4ish for the stake nuts alone when I could get them and was sourcing bearings elsewhere.

Im not gonna try and do it as it's way out of my capability as an amateur mechanic! I've found a wheel bearing kit on ebay for £13 which consists of a stake nut, 3 circular components and what looks like a small pouch of grease?

Why does the nut have to be undone by 90 degrees after you've set it to 52Nm with a torque-wrench?...

Also, I seem to remember when I had it done by a crap local mechanic a couple of years ago that he had to push the piston back to do the job; apparently he should have removed the filler cap on the master cylinder before doing this as there's a danger of knackering it if the filler-cap is left on?...

Justin wrote:Why does the nut have to be undone by 90 degrees after you've set it to 52Nm with a torque-wrench?...

52Nm makes sure everything is seated "home", i.e. all the bits are fully pushed on. That is exerting a chunk of compression force on the hub components though (in the direction down the axis of the stub axle) so by releasing it by 90degrees you are giving a tiny bit of wiggle room. The 90degrees will have been calculated by knowing the pitch of the thread, then calculating how much "slop" should be included.

It's the reason having a locking nut is so important, the nut itself isn't tight, it's a thing to set a distance.

Filler cap, it's not a super problem, but best to have it loose yes.

Thanks Chris, you're a true gentlemen...

If you have a wrench that is 1 meter long and you have 5kgs pressing down on the end of it,that is 50 Newton Metres.......(I think)

Adjustable tapered bearings are unusal, most are not adjustable and need huge torque, its more than likely the mechanic do not know what to do with it and just adjusted it incorrectly or didn't stake it. The stake nut should hold it unless it been staked in the same point multiple times

Thanks ride-on, the nut looks as if it's been staked at least 3 times! My car made two huge BANGS yesterday from said wheel but still seems to be driving ok.

Im gonna leave it off the road until my wheel bearing kit arrives from ebay and then limp it down the road to an "old school" mechanic that my friend put me onto...

Also, I dont see how a mechanic could correctly torque it without referring to a manual for the specs?

Done by feel, when you know what it feels like never a problem

What, you mean when you torque it?

With experience you just know when it is right. Torqueing them down will normally be right but in some cases they can be an issue that causes it not to seat correctly. Without experience you can only rely on setting the torque correctly.

My wheel bearing kit arrived at dinner time today and I noticed that the 24mm hub-nut is silver and has a blue plastic collar on the top edge; Im guessing this is a self-locking nut and that I wont need nor be able to stake it into place?...

It is a nylock. What brand of bearings did you buy?